CN207690246U - Alarm system and its alarm signal light converting transmission device - Google Patents
Alarm system and its alarm signal light converting transmission device Download PDFInfo
- Publication number
- CN207690246U CN207690246U CN201820022774.8U CN201820022774U CN207690246U CN 207690246 U CN207690246 U CN 207690246U CN 201820022774 U CN201820022774 U CN 201820022774U CN 207690246 U CN207690246 U CN 207690246U
- Authority
- CN
- China
- Prior art keywords
- signal light
- alarm signal
- transmission device
- light converting
- alarm
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Landscapes
- Alarm Systems (AREA)
Abstract
The utility model discloses alarm signal light converting transmission devices to be additionally operable to connect external alert host by the electrooptic conversion module of long distance transmission alarm signal for connecting multiple external alert detectors；The alarm signal light converting transmission device includes window comparator and electro-optical conversion circuit, for exporting the first signal in the alarm signal light converting transmission device, it is additionally operable to export second signal in alarm signal light converting transmission device open circuit or short circuit, to realize the conversion of different alarm, detection and the physical isolation of alarm signal are realized.Due to window comparator the alarm signal light converting transmission device open a way or short circuit when export second signal, no matter alarm signal light converting transmission device open circuit or short circuit all realize warning function, meet the requirement of security protection standard.
Description
【Technical field】
The utility model is related to public safety monitoring technology field more particularly to a kind of alarm system and its alarm signal light
Converting transmission device.
【Background technology】
With being continuously increased for security protection application scenarios, the key protective regions such as some government bodies' unit, museum, exhibition centers
Requirement of the domain unit to safety technological guards such as locality protection, perimeter protections is continuously improved, therefore these units can all be installed greatly
Type alarm system, including multiple alarm host machines and multiple alarm detectors；Have at present and is come using the switching value of electrical-optical conversion module
Transmit alarm signal (i.e. on-off model).
Inventor has found during studying the utility model, uses the switch of electrical-optical conversion module in the prior art
It measures to transmit the mode of alarm signal, does not meet the requirement of security protection standard.The requirement of security protection standard, which is alarm circuit, should open circuit
Warning function has short circuit warning function again, and above-mentioned function cannot be realized simultaneously if being transmitted simply by switching value.
In the prior art, alarm host machine is typically only capable to be directly connected to 10 or so probes, when popping one's head in large number of, needs
Alarm host machine is accessed by expansion module, that is, defence area expansion board of alarm system, usual every piece of defence area expansion board can access 8
A probe needs to install 30 pieces of defence area expansion boards to realize if an alarm system needs 250 probes of management, and each piece anti-
Area's expansion board is connected by two data lines and the data communication bus interface of alarm host machine respectively, due to the data of alarm host machine
Only there are one interface, 30 pieces of defence area expansion boards are connected in parallel in use, being equivalent to data bus interface communication bus interface simultaneously
30 data lines.But these data lines (are under normal circumstances 1500 meters, but can with being easy to be disturbed, have distance limitation
Extend distance by increasing signal extender, but total length still can be restricted), encounter thunder and lightning weather and be easy to be damaged
Place is improved not to the utmost, all significantly affects the using effect and reliability of alarm system.
【Utility model content】
In order to solve the above-mentioned mode for transmitting alarm signal using switching value electrical-optical conversion module, alarming line is not met
Road should have open circuit warning function, there is the technical issues of security protection standard of short circuit warning function, the utility model embodiment again
A kind of alarm signal light converting transmission device is provided, including：
Multiple alarm detectors；
The alarm signal light converting transmission device being connect with the alarm detector, connects for passing through electrical-optical conversion module
Alarm host machine；The alarm signal light converting transmission device includes window comparator, in the alarm signal light converting transmission
The first signal is exported when device is normal, is additionally operable to the second letter of output in alarm signal light converting transmission device open circuit or short circuit
Number, to realize the conversion of different alarm.
Optionally, the alarm signal light converting transmission device further includes end resistance Rx, first resistor R14, relay
RL1, the second triode Q2 and the first triode Q1；
Window comparator has first threshold and second threshold, the end when the alarm signal light converting transmission device is normal
The resistance Rx connections electrical-optical conversion module, the end resistance Rx form bleeder circuit, first resistor with first resistor R14
Voltage on R14 is more than first threshold and is less than second threshold, and the first signal of the window comparator output is low level, institute
The second triode Q2 cut-offs, the first triode Q1 conductings are stated, relay RL1 is closed；When the alarm signal light converting transmission device
When alarm, the end resistance Rx is disconnected, and voltage is 0V on first resistor R14, and the second signal of window comparator output is height
Level, the second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected；When the alarm signal light is converted
When transmitter short circuit, voltage is more than second threshold on the first resistor R14, and the second signal of the window comparator output is
High level, the second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected.
Optionally, the alarm signal light converting transmission device further includes power circuit, and power circuit includes steady for exporting
The Voltage stabilizing module of constant voltage.
Optionally, the Voltage stabilizing module is used to AC24V being converted to DC12V.
Optionally, the alarm signal light converting transmission device further includes lightning-protection module.
Optionally, the alarm signal light converting transmission device further includes isolation module.
In order to solve the above technical problems, the utility model also provides a kind of alarm system, including alarm host machine and alarm signal
Number light converting transmission device, the alarm signal light converting transmission device include：
Multiple alarm detectors；
The alarm signal light converting transmission device being connect with the alarm detector, connects for passing through electrical-optical conversion module
The alarm host machine；The alarm signal light converting transmission device includes window comparator, for being converted in the alarm signal light
The first signal is exported when transmitter is normal, is additionally operable to export second in alarm signal light converting transmission device open circuit or short circuit
Signal, to realize the conversion of different alarm.
Optionally, the alarm signal light converting transmission device further includes end resistance Rx, first resistor R14, relay
RL1, the second triode Q2 and the first triode Q1；
Window comparator has first threshold and second threshold, the end when the alarm signal light converting transmission device is normal
The resistance Rx connections electrical-optical conversion module, the end resistance Rx form bleeder circuit, first resistor with first resistor R14
Voltage on R14 is more than first threshold and is less than second threshold, and the first signal of the window comparator output is low level, institute
The second triode Q2 cut-offs, the first triode Q1 conductings are stated, relay RL1 is closed；When the alarm signal light converting transmission device
When alarm, the end resistance Rx is disconnected, and voltage is 0V on first resistor R14, and the second signal of window comparator output is height
Level, the second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected；When the alarm signal light is converted
When transmitter short circuit, voltage is more than second threshold on the first resistor R14, and the second signal of the window comparator output is
High level, the second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected.
Optionally, further include cross box, be built-in with the electrical-optical conversion module, the end resistance Rx accesses conversion
The switching value of plate, change-over panel output is connected to the electrical-optical conversion module, passes through electrical-optical conversion module transmitting switch amount to institute
State alarm host machine.
Optionally, the 16 tunnel alarm signal of electrical-optical conversion module parallel transmission.
The advantageous effect of the utility model embodiment is：The case where being different from the prior art, the utility model embodiment
Alarm signal light converting transmission device for connecting multiple external alert detectors, be additionally operable to through long distance transmission alarm signal
Electrical-optical conversion module connect external alert host；The alarm signal light converting transmission device includes window comparator, is used for
The alarm signal light converting transmission device exports the first signal when normal, is additionally operable to open in the alarm signal light converting transmission device
Second signal is exported when road or short circuit, to realize the conversion of different alarm.Since window comparator is in the alarm signal
Output second signal exports second signal when light converting transmission device opens a way or is short-circuit, realizes the conversion to different alarm,
No matter warning function is all realized in alarm signal light converting transmission device alarm (open circuit) or short circuit, meet the requirement of security protection standard.
【Description of the drawings】
Fig. 1 is the structure diagram for the alarm signal light converting transmission device that the utility model embodiment provides；
Fig. 2 is the alarm signal light converting transmission device for the alarm signal light converting transmission device that the utility model embodiment provides
Circuit diagram；
Fig. 3 is the structure diagram for the alarm system that the utility model embodiment provides.
【Specific implementation mode】
In order to make the purpose of the utility model, technical solutions and advantages more clearly understood, below in conjunction with attached drawing and implementation
Example, the present invention will be further described in detail.It should be appreciated that specific embodiment described herein is only explaining this
Utility model is not used to limit the utility model.
Unless otherwise defined, technical and scientific term all used in this specification and the skill for belonging to the utility model
The normally understood meaning of technical staff in art field is identical.Art used in the description of the utility model in this specification
Language is intended merely to the purpose of description specific embodiment, is not intended to limitation the utility model.Art used in this specification
Language "and/or" includes any and all combinations of one or more relevant Listed Items.
Embodiment one
Fig. 1 is please referred to, Fig. 1 is the structural frames for the alarm signal light converting transmission device 10 that the utility model embodiment provides
Figure.Alarm signal light converting transmission device 10 is additionally operable to alarm by long distance transmission for connecting multiple external alert detectors
The electrical-optical conversion module of signal connects external alert host；The alarm signal light converting transmission device 10 includes window comparator
12, for exporting the first signal when the alarm signal light converting transmission device 10 is normal, it is additionally operable in the alarm signal light
Converting transmission device 10 opens a way or exports second signal when short-circuit, to realize the conversion of different alarm.Due to window comparator
12 export second signal in the alarm signal light converting transmission device 10 open circuit or short circuit exports second signal, realizes to not
It is accorded with the conversion of alarm signal no matter alarm signal light converting transmission device 10 is alarmed (open circuit) or warning function is all realized in short circuit
Close the requirement of security protection standard.Alarm signal light converting transmission device 10 realizes existing open circuit warning function, and has short-circuit alarming work(
Energy.
Specifically, multiple alarm detectors 11 can be infrared, microwave, infrared microwave dual technology detector, vibration detector
With standing wave detector etc..
Fig. 2 is please referred to, Fig. 2 is the alarm signal light for the alarm signal light converting transmission device that the utility model embodiment provides
The circuit diagram of converting transmission device.The alarm signal light converting transmission device 10 further includes end resistance Rx, first resistor
R14, relay RL1, the second triode Q2 and the first triode Q1；
Window comparator 12 has first threshold and second threshold, when the alarm signal light converting transmission device 10 is normal
The end resistance Rx connections electrical-optical conversion module, the end resistance Rx and first resistor R14 composition bleeder circuits, first
Voltage on resistance R14 is more than first threshold and is less than second threshold, and the first signal of the window comparator output is low electricity
It is flat, the second triode Q2 cut-offs, the first triode Q1 conductings, relay RL1 closures；It converts and passes when the alarm signal light
When defeated device 10 is opened a way, the end resistance Rx is disconnected, and the upper voltages of first resistor R14 are 0V, and the second of the output of window comparator 12
Signal is high level, the second triode Q2 conductings, and the first triode Q1 cut-offs, relay RL1 is disconnected；When the alarm signal
When 10 short circuit of number light converting transmission device, the upper voltages of the first resistor R14 are more than second threshold, the output of the window comparator 12
Second signal be high level, the second triode Q2 conducting, the first triode Q1 cut-offs, relay RL1 disconnects.
Alarm signal light converting transmission device 10 is illustrated by taking Fig. 2 as an example below.As shown in Fig. 2, chip U2A, U2B and electricity
It hinders R7, R8, R15 and forms window comparator 12, the first threshold values of window comparator 12 is 1.67V, second threshold 3.33V.Report
When alert signal light converting transmission device 10 is in normal, alarm signal light converting transmission device 10 passes through end resistance Rx access conversions
In plate, end resistance Rx and first resistor R14 form bleeder circuit, and the voltage on first resistor R14 is 2.5V, window comparator
12 outputs are low level, the second triode Q2 cut-offs, the first triode Q1 conductings, relay RL1 closures.When alarm signal light turns
When changing the open circuit of transmitter 10, end resistance Rx is disconnected, and the upper voltages of R14 are 0V, and window comparator 12 exports high level, the two or three pole
Pipe Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected.When 10 short circuit of alarm signal light converting transmission device, the first electricity
It is 5V to hinder voltage on R14, and window comparator 12 exports high level, and the first triode, Q1 cut-offs, relay is connected in the second triode Q2
Device RL1 is disconnected.
The switching value for being connected to end resistance Rx is converted into pure switching value by the realization of window comparator 12 as a result,.
The alarm signal light converting transmission device 10 further include power circuit, lightning-protection module and isolation mode it is in the block a kind of or
It is a variety of.It is Voltage stabilizing module that power circuit, which includes for exporting P1 in the Voltage stabilizing module P1, Fig. 2 of burning voltage, for turning AC24V
It is changed to DC12V.In power circuit, resistance R2, light emitting diode D2 constitute power indicating circuit.Diode D4, D5 composition isolation
Module, effect are isolation.Realize the physical isolation of alarm host machine interface and alarm detector 11.Resistance R3, R4, varistor
RV1, capacitance C4 form lightning-protection module, play lightning protection.
By above-described embodiment provide alarm signal light converting transmission device 10, compared with the existing technology in pass through alarm system
The expansion module of system, that is, defence area expansion board accesses alarm host machine, used data line have be easy to be disturbed, have distance limitation,
It encounters thunder and lightning weather and is easy to be damaged etc. and improve place not to the utmost, such as transmit alarm signal using switching value electrical-optical conversion module
(i.e. on-off model), by security protection standard requirement, alarm circuit should have open circuit warning function, there is short circuit warning function again,
Above-mentioned function cannot be realized simultaneously if being transmitted simply by switching value.
The alarm signal light converting transmission device 10 that the utility model embodiment provides, passes through switching value electrical-optical conversion module
Alarm signal is transmitted, solves the problems, such as that electrical-optical conversion module transmits alarm signal by the circuit of window comparator 12, and is led to
It crosses the transmission of electrical-optical conversion module and solves the easy of alert data line and be limited, be subject to by electromagnetic interference, line length
The problems such as thunder and lightning damages；It can solve to transmit alarm signal (on-off model) by switching value electrical-optical conversion module again, it cannot
Meet the requirement of shelter to alarm circuit in security protection standard, i.e. alarm circuit there should be open circuit warning function, there is short-circuit report again
Alert function.
The utility model embodiment provide alarm signal light converting transmission device 10, realize alarm interface from dielectric to
The conversion of optical medium prevents destruction of the thunder and lightning to alarm interface substantially；Theoretically can unlimited long distance transmission alarm report
Alert input signal；Realize the physical isolation of alarm host machine interface and probe；Solving switching value electrical-optical conversion module cannot be simultaneously
Realize open circuit, short-circuit warning function.Core circuit is the circuit of window comparator, realizes the conversion of signal, simple and reliable.
Embodiment two
The utility model embodiment also provides a kind of alarm system 100, is led as shown in figure 3, alarm system 100 includes alarm
Alarm signal light converting transmission device 10 in machine 30 and above-described embodiment one.
Alarm signal light converting transmission device 10 is used to connect the alarm detector 11 of multiple alarm systems 100, is additionally operable to lead to
The electrical-optical conversion module that long-distance transmits alarm signal connects 100 alarm host machine of alarm system；；The alarm signal light turns
It includes window comparator 12 to change transmitter 10, for the first letter of output when the alarm signal light converting transmission device 10 is normal
Number, it is additionally operable to export second signal in the alarm signal light converting transmission device 10 open circuit or short circuit, to realize different alarms
The conversion of signal.Since window comparator 12 when the alarm signal light converting transmission device 10 opens a way or is short-circuit, believe by output second
Second signal number is exported, realizes the conversion to different alarm, no matter the alarm of alarm signal light converting transmission device 10 (is opened
Road) or short circuit all realize warning function, meet the requirement of security protection standard.Alarm signal light converting transmission device 10 realizes existing open
Road warning function, and have short circuit warning function.
The other technical characteristics of alarm signal light converting transmission device 10 in above-described embodiment one and its effect brought are asked
Reference implementation example one, this will not be detailed here.
The alarm system 100 further includes cross box 20, is built-in with the electrical-optical conversion module 40, the end electricity
It hinders Rx and accesses change-over panel (not shown), the switching value of change-over panel output is connected to the electrical-optical conversion module 40, passes through electrical-optical
40 transmitting switch amount of conversion module is to the alarm host machine 30.
40 parallel transmission of electrical-optical conversion module, the 16 tunnel alarm signal realizes that electrical-optical conversion module transmits the alarm of 16 tunnels
Signal.
The alarm system 100 that the utility model embodiment provides, including alarm signal light converting transmission device 10, pass through switch
Electrical-optical conversion module is measured to transmit alarm signal, the circuit for passing through window comparator 12 solves the transmission alarm of electrical-optical conversion module
The problem of signal, and solve the easy to be long by electromagnetic interference, circuit of alert data line by the transmission of electrical-optical conversion module
Degree is limited, is subject to the problems such as thunder and lightning damage；It can solve to transmit alarm signal by switching value electrical-optical conversion module again
(on-off model) cannot meet the requirement of shelter to alarm circuit in security protection standard, you can cannot be simultaneously to solve alarm circuit
Satisfaction should have open circuit warning function to have short circuit warning function again.
The above is only the preferred embodiment of the utility model only, is not intended to limit the utility model, all at this
All any modification, equivalent and improvement etc., should be included in the utility model made by within the spirit and principle of utility model
Protection domain within.
Claims (10)
1. a kind of alarm signal light converting transmission device, which is characterized in that for connecting multiple external alert detectors, be additionally operable to lead to
The electrical-optical conversion module that long-distance transmits alarm signal connects external alert host；The alarm signal light converting transmission device
It is additionally operable to described including window comparator for exporting the first signal when the alarm signal light converting transmission device is normal
Alarm signal light converting transmission device opens a way or exports second signal when short-circuit, to realize the conversion of different alarm.
2. alarm signal light converting transmission device as described in claim 1, which is characterized in that the alarm signal light converting transmission
Device further includes end resistance Rx, first resistor R14, relay RL1, the second triode Q2 and the first triode Q1；
Window comparator has first threshold and second threshold, the end resistance when the alarm signal light converting transmission device is normal
The Rx connections electrical-optical conversion module, the end resistance Rx and first resistor R14 form bleeder circuit, on first resistor R14
Voltage be more than first threshold and be less than second threshold, the first signal of window comparator output is low level, described the
Two triode Q2 cut-offs, the first triode Q1 conductings, relay RL1 are closed；When the alarm signal light converting transmission device is opened a way
When, the end resistance Rx is disconnected, and voltage is 0V on first resistor R14, and the second signal of window comparator output is high level,
The second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected；When the alarm signal light converting transmission
When device short circuit, voltage is more than second threshold on the first resistor R14, and the second signal of the window comparator output is high electricity
It is flat, the second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 disconnections.
3. alarm signal light converting transmission device as claimed in claim 1 or 2, which is characterized in that the alarm signal light conversion
Transmitter further includes lightning-protection module.
4. alarm signal light converting transmission device as claimed in claim 3, which is characterized in that the lightning-protection module includes third electricity
Hinder R3, with the 3rd resistor R3 series winding the 4th resistance R4, with the 3rd resistor R3 and even the first varistor RV1 and
With the 3rd resistor R3 and the 4th capacitance C4 even.
5. alarm signal light converting transmission device as claimed in claim 1 or 2, which is characterized in that the alarm signal light conversion
Transmitter further includes power circuit, and power circuit includes the Voltage stabilizing module for exporting burning voltage.
6. alarm signal light converting transmission device as claimed in claim 5, which is characterized in that the Voltage stabilizing module is used for will
AC24V is converted to DC12V.
7. alarm signal light converting transmission device as claimed in claim 1 or 2, which is characterized in that further include light conversion isolation mode
Block.
8. a kind of alarm system, including alarm host machine and alarm signal light converting transmission device, which is characterized in that the alarm system
Including：Multiple alarm detectors, the alarm signal light converting transmission device being connect with the alarm detector, for passing through electrical-optical
Conversion module connects the alarm host machine；The alarm signal light converting transmission device includes window comparator, in the report
Alert signal light converting transmission device exports the first signal when normal, is additionally operable in alarm signal light converting transmission device open circuit or short
Second signal is exported when road, to realize the conversion and transmission of different alarm.
9. alarm system as claimed in claim 8, which is characterized in that the alarm signal light converting transmission device further includes end
Resistance Rx, first resistor R14, relay RL1, the second triode Q2 and the first triode Q1；
Window comparator has first threshold and second threshold, the end resistance when the alarm signal light converting transmission device is normal
The Rx connections electrical-optical conversion module, the end resistance Rx and first resistor R14 form bleeder circuit, on first resistor R14
Voltage be more than first threshold and be less than second threshold, the first signal of window comparator output is low level, described the
Two triode Q2 cut-offs, the first triode Q1 conductings, relay RL1 are closed；When the alarm signal light converting transmission device is opened a way
When, the end resistance Rx is disconnected, and voltage is 0V on first resistor R14, and the second signal of window comparator output is high level,
The second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 are disconnected；When the alarm signal light converting transmission
When device short circuit, voltage is more than second threshold on the first resistor R14, and the second signal of the window comparator output is high electricity
It is flat, the second triode Q2 conductings, the first triode Q1 cut-offs, relay RL1 disconnections.
10. alarm system as claimed in claim 9, which is characterized in that 16 tunnel of the electrical-optical conversion module parallel transmission alarm
Signal.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820022774.8U CN207690246U (en) | 2018-01-05 | 2018-01-05 | Alarm system and its alarm signal light converting transmission device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201820022774.8U CN207690246U (en) | 2018-01-05 | 2018-01-05 | Alarm system and its alarm signal light converting transmission device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN207690246U true CN207690246U (en) | 2018-08-03 |
Family
ID=62991403
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201820022774.8U Active CN207690246U (en) | 2018-01-05 | 2018-01-05 | Alarm system and its alarm signal light converting transmission device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN207690246U (en) |
-
2018
- 2018-01-05 CN CN201820022774.8U patent/CN207690246U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN101576416B (en) | System for monitoring contact temperature of high-voltage switch cabinet on line | |
| CN203850925U (en) | Communicator for lightning protection remote early-warning monitoring box | |
| CN205620036U (en) | Dry -type transformer temperature rise detection device | |
| CN100353639C (en) | Photoelectricity triggering and detecting system for static reactive-load compensation equipment based on multi-mode optical fibre | |
| CN105676054A (en) | Cable reversal connection and short-circuit detection circuit | |
| CN206601435U (en) | The portable over-pressed harvester of full optics and system | |
| CN207690246U (en) | Alarm system and its alarm signal light converting transmission device | |
| CN203811289U (en) | Temperature on-line monitoring device for low-voltage power supply surge protector | |
| CN106253080A (en) | A kind of intelligent temperature measurement switch cubicle | |
| CN210774332U (en) | Phase-sensitive optical time domain reflectometer signal acquisition device for transformer substation monitoring | |
| CN109324257A (en) | Residual current on-Line Monitor Device | |
| CN102495332B (en) | System and method for sampling unbalanced current | |
| CN108230595B (en) | Intrusion prevention alarm device and system | |
| CN109858600A (en) | A kind of low-power consumption burglar alarm RFID label tag | |
| CN207650947U (en) | A kind of anti-intrusion warning device and system | |
| CN204887653U (en) | Street lamp leakage detection system | |
| CN210089750U (en) | Food data acquisition system | |
| CN209148040U (en) | A kind of intelligent water leakage monitoring device | |
| CN209586595U (en) | A kind of blower lightning protection online environment monitoring device | |
| CN209117059U (en) | A kind of vehicle environment monitoring system | |
| CN209674396U (en) | A kind of low-power consumption burglar alarm RFID label tag | |
| CN207019817U (en) | A kind of temperature sensor for high-tension line | |
| CN206162802U (en) | Communal facility protection system | |
| CN206773067U (en) | A kind of intelligent electric meter monitoring device | |
| CN207817060U (en) | A kind of online electrostatic potential tester |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |